Hydrocyanation of olefinic compounds



, Where -no such.-activating:influence exists. lIt

:lsalzente jan. j l l v any, Wilmington, Del., a colfinvention :relatesto v: a new. 12116. S 91 .preparinenitnles by addition of...-hysi rpgenQ5/L- ani'de :to `oleni'c bonds.; and to new catalysts ,fior carryingout-' :thiseaction application is, a` contnuationrn-patt 1vof ourapplication "Serial `lSIuinber 373503', led July '7;"11948, nowabandoned. l

It known' that addition-of hydrogenyanide to activated "double `loonls,vi. e.; :to ethyl'enic I bonds adjacentrtolan.activating groupsuch as 10ijloopnyl with;hydrogencyanidel V,' Ihese'the'nitrile'oracyloxyvgroups;proceeds with relctsare new and thSf-fbrlDelft fof 'this inven- `at'i'e ease: 'On thenther hand; ituisextremely lY dijcult to add hydrogen cyanide to .a double tional in' amonoorrpolyolefinic hydrocarbon aeeavso 3 contain, depending upon theconditions of formation, from 23% to 44% cobalt and from 16% to 38%nitrogen. Moreover, on treatment with potassium cyanide solution togive, as already mentioned, potassium cobalt cyanide, the complexesevolve carbon monoxide, unlike cobalt cyanide. Cobalt cyanide is not acatalyst for the hydrocyanation of olens, whereas the complexes justdescribed are. It is possible that these compounds are formed in situwhenever an olen is treated with hydrogen cyanide in the presence ofcobalt carbonyl, but this has not been demonstrated.

Other suitable catalysts containing cobalt carbonyl are the heavy metalsalts f cobalt carbonyl hydride (Z. Anorg. Chem., "232', 17 1937) y),for example, the mercury salt of cobalt carbonyl hydride, which has theformula Hg[Co(CO),4]2.

Further suitable catalysts are the cobalt car-` bonyl hydride-butadieneaddition products described in application Serial Number 779,837, filedlby Prichard on October 14, 1947. These latter complexes are formedbyreacting butadiene with cobalt carbonyl in the presence of a secondaryalcohol and their probable molecular formula is CaHvOrCo. On the basisof present information, there may be used as catalyst in the process 'ofthis invention any material containing cobalt 'carbonyl and in which thecobalt content is between about and 45%. The cobalt carbonyl catalyst isused in proportions, based on the ethylenic compound, between about 0.01and 0.3 mole per mole, although more can be used if desired. A generallyuseful range is between 0.03 and 0.2 mole of catalyst per mole ofunsaturate. Surprisingly, the free metal is ineffective in thehydrocyanation reaction at the low temperatures and pressures at whichthe cobalt carbonyl catalysts are effective.

The reaction is preferably carried out in a substantially anhydrousmedium although some Water, for example the small amount (2-3%) presentin commercial liquid hydrogen cyanide, is not usually detrimental. Evenmuch larger amounts of water may be present but in such cases theconversion is in general sharply decreased. The highest conversions areobserved vwhen the hydrogen cyanide is at least partly dried, forexample by passing it through a dehydrating agent, and also when thevolatile acidic stabilizers sometimes present in it areat least -partlyremoved, for example by bubbling nitrogen through the hydrogen cyanidefor a few minutes.

While the reaction takes place readily with- -out addition of anextraneous solvent, it has been observed that better yields of nitrilesometimes result when the system comprises a solvent for the reactantsand catalyst, probably because dilution tends to reduce the formation ofpolymers. Any aliphatically saturated organic liquid substantially inerttowards reactants and catalysts may be used, in particular hydrocarbonssuch as benzene, toluene, hexane, cyclohexane, etc.; ethers, such asdipropyl ether, dibutyl ether, etc.; or other solvents such astetrahydrofuran, etc. The solvent may be used in any desiredproportions, such as between 0.5 mole and 10 moles or more based on theethylenic compound.

The hydrocyanation reaction normally proceeds very slowly at lowtemperature, and to achieve a practical reaction rate it is generallydesirable to operate above about 50 C. The upper limit of temperature isdictated only by the decomposition point of the reactants. In practice,however. it is seldom desirable to op- 4 crate above 200 C. A generallyuseful temperature range is that between 80 and 150 C. It may be notedthat in general the catalysts decompose at relatively low temperature.It is possible that'they are converted during the reaction to othercobalt derivatives having catalytic Y activity.

Since hydrogen cyanide boils at 26 C. and since the other reactants andsolvents are in general volatile, it is necessary to operate in aclosed, pressure-resistant vessel. Any suitable pressure vessel such asthe conventional autoclaves or bombs, may be used. Reactors designed forcontinuous or semi-continuous operation may be used. For example, thecobalt carbonyl catalyst may be injected continuously under pressureinto the reaction zone as a solution in. an inert solvent such asbenzene, the spent catalyst, which is in the form of a finely dividedpowder, may be filtered from the reaction product and any unreactedolefin and hydrogen cyanide recycled. If desired, agitation Amay beprovided either internally or externally.

The reaction proceeds at the autogenous pressure of the reactants and noadditional pressure is necessary, although such may be used if desired.In this case, pressure may be provided by any inert gas such as nitrogenor air, or by an excess of a volatile unsaturate such as ethylene. Sincethe autogenous pressure of the reactants is not very high, itisunnecessary to use equipment designed for extremely high pressures.

The reaction time depends upon several factors including the nature ofthe unsaturate and the temperature. In .general some nitrile will haveformed within one ortwo hours at temperatures within the preferredrange, i. e., above A 80 C., and after 6 to 10 hours there is littlefur- `ther reaction and there is the danger of decomposing the reactionproduct. The nitrile or mix- `ture of nitriles which form may beisolated by Aany suitable method such as direct distillation,

steam distillation, crystallization if the nitriles are solid, etc. Theunused hydrogen cyanide and ethylenic compound may be recovered and usedagain. As has already been mentioned, the cobalt carbonyl is decomposed,at least partly, during the reaction.

It has been observed that, in certain cases, the activity of the cobaltcarbonyl catalysts may be enhanced by the presence in the reactionmixture of teritiary arylphosphines or arsines. The tertiaryarylphosphine or arsine is desirably used in amounts of 0.01-0.3 mole,preferably 0.03-0.2 mole, per mole of insaturate. The iniluence of thesepromoters is shown in some of the examples.

The following examples in which parts are by weight are illustrative ofthe invention.

EXAMPLE I A stainless steel reactor was charged with 40.5 parts ofhydrogen cyanide, previously blown with nitrogen for two minutes anddried over calcium chloride, 86 parts of Lil-butadiene and 17.1 parts ofcobalt tetracarbonyl, Co2(CO)a, these reactants being in the molar ratioof 1.00/ LOG/0.034, respectively. The tightness of the reactor wastested by pressuring with nitrogen and then venting to atmosphericpressure, leaving nitrogen as the gas above the reactants before sealingthe reactor. The reactor was heated at 60 C. for one hour, then at C.for one hour, then at 100 C. for one hour and iinally at 120 C. for /2hours. After venting and cooling, the reacpound analyzing correctly forZ-methylglutaric acid.

EXAMPLE VI A stainless steel reactor was charged with 54 parts ofhydrogen cyanide, 114 parts of butene-l, 17.1 parts of cobalttetracarbonyl and 66 parts of benzene. The reactor was purged once withnitrogen, closed and raised to a temperature of 100 C. where it wasmaintained with agitation for hours. The product was filtered anddistilled and the portion boiling between 92 and 140 C. wasrefractonated. There was obtained 3.3 parts of Valeronitrile boiling at138- 144 C. and having a refractive index 11h25 of 1.3922 to 1.4000.

Under somewhat different conditions involving higher temperatures andabsence of solvent, the addition of hydrogen cyanide to butene-lproceeds in the so-called normal manner, i. e., it gives as the reactionproduct 2-methy1butyronitrile, CHaCH(CN)CH2-CH3, rather thanvaleronitrile. For example, when 56 parts of 1-butene, 13.9 parts ofhydrogen cyanide (the commercial product containing about 2.5% of water)and 17 parts of cobalt tetracarbonyl were reacted for 8 hours at 130 C.,there was obtained a 26.8% con- Version of 2-methylbutyronitrile. Thisproduct when purined boiled at 126 C. and had a refractive index 111,251.3882 and a specific gravity It contained by analysis 16.06% nitrogenas compared with the calculated value, 16.9%.

The procedure just described but using carefully dried, stabilizer-freehydrogen cyanide prepared from sodium cyanide and sulfuric acid gave a67.5% conversion to 2methylbutyronitrile.

EXAMPLE VII A silver-lined pressure vessel was charged with 27 parts ofhydrogen cyanide and 17 parts of cobalt tetracarbonyl. The vessel waspressured with 110 atmospheres of ethylene at 24 C. and heated for onehour each at 70 C., 80 C., and 90 C. and finally for 7 hours at 100 C.,in order to avoid the violent reaction experienced on raising thetemperature too rapidly. The maximum pressure reached was 260atmospheres at 80 C. and the final pressure was 195 atmospheres at 100C. The reaction product was iiltered from the catalyst and distilled.YThere was obtained 35 parts (64% conversion of the hydrogen cyanide) ofpropionitrile, B. P. 96-98 C., 1125 1.3682. f

EXAMPLE VIII A stainless steel reaction vessel was charged with 104parts of freshly distilled styrene, 2 parts of hydroquinone, 17 parts ofcobalt tetracarbonyl and 27 parts of hydrogen cyanide, and heated for 8hours at 130 C. and S80-355 lbs/sq. in. internal pressure. The vesselwas then cooled, opened and the contents were rinsed out with benzene.After filtering oi the spent catalyst, the ltrate was distilled and 68.5parts (52.2% yield) of 2-phenylpropionitrile, B. P. 117 C. at mm.pressure, was isolated. It contained 10.79% nitrogen as compared withthe calculated value of 10.7%.

EXAMPLE IX A stainless steel reactor was charged with 56 parts ofbutene-2, 13.5 parts of hydrogen cyanide, 17 parts ofrcobalttetracarbonyl and 8.5 parts of triphenyl-phosphine, and heated for 9hours at 130 C., the maximum pressure being 39 atmospheres. The productwas :liltered and distilled to give 17.8 parts (43% yield) of2-methylbutyronitrile.

A similar experiment but without the triphenyl-phosphine gave a 9% yieldof 2-methylbutyronitrile.

EXAMPLE X A silver-lined pressure Vessel was charged with 41 parts of3-pentenenitrile, 27 parts of hydrogen cyanide, 17 parts of cobalttetracarbonyl and 8.5 parts of triphenylphosphine and heated for 8 hoursat 130 C. Working up of the reaction product gave 8.3 parts (15.4%yield) of 2-methylglutaronitrile.

A similar experiment but without the triphenylphosphine gave a 7%conversion tn 9.- methylglutaronitrile.

EXAMPLE XI A silver-lined reaction vessel was cooled in a carbondioxide-acetone bath, ushed with nitrogen and charged with 17 parts ofcobalt tetracarbonyl and 27 parts of hydrogen cyanide prepared fromsodium cyanide and sulfuric acid and redistilled over phosphoruspentoxide. The vessel was then evacuated While in the cold bath andcharged with 150 parts of propylene. Upon heating the vessel to 130 C.the internal pressure rose to atmospheres, then dropped to 90atmospheres in one-half hour and remained there for 14.5 hours. Thevessel was then cooled, opened, its contents rinsed out with ether,ltered and distilled. There was obtained 45 parts (65% conversion ofhydrogen cyanide) of isobutyronitrile boiling at 10D-105 C., 111,251.372. Its nitrogen content was 19.86% as compared with the calculatedvalue 20.3%.

When this experiment was repeated with addition of 8.5 parts oftriphenylphosphine, the reaction ashed suddenly at a temperature of 70C. to a temperature of 183 C. and a pressure of 300 atmospheres. Thevessel was cooled to C. and maintained there for 14.5 hours at apressure of 110-100 atmospheres. There was recovered 52 parts (75%conversion) of isobutyronitrile.

EXAMPLE XII A cobalt carbonyl-hydrogen cyanide complex was prepared asfollows: A weighed amount of cobalt tetracarbonyl was added to hydrogencyanide maintained at the reuxing temperature (26 C.) and the gasesevolved were passed through a cold trap to remove the entrained hydrogencyanide and then through a dry test meter. The cobalt carbonyl was addedover a one hour period, and the gas evolution continued for about 11/2hours more. A total of 2.5 moles of gas was evolved per atom of cobaltin the cobalt carbonyl used. Gas samples were taken at intervals andanalyzed in an Orsat apparatus. Only hydrogen and carbon monoxide werepresent in appreciable amount (approximately in 1:4 ratio), thefollowing gas sample 'being typical of the samples analyzed: carbondioxide 0.2, unsaturate 1.0, oxygen 0.3, hydrogen 18.8, carbon monoxide77.4, residual gas 2.2. The solid reaction product (cobaltcarbonyl-hydrogen cyanide complex) was a blue powder containing 44.04%cobalt and 18.75% nitrogen which evolves carbon monoxide on treatmentwith aqueous potassium cyanide. A 13.5 part sample of this reactionproduct was placed in a pressure vessel with 27 parts of hydrogencyanide 9. and 1.50. `parts =of propylene. After' 15A hours. at V130 C.there was obtained ll'partsriilU/t converfi sion) of isobutyronitrile.Other cobalt carbonyl-hydrogen cyanide complexes were prepared in thesame manner, except that in one case thev initial 4reaction temperaturewas 26 C. and 4no fur-ther external heat Was applied and in another casethe reaction temperature was C. Carbon monoxide vand hydrogen wereevolved in substantially the same .relative proportions asin the aboveexperiment. The reaction products were again blue. powders containing,respectively, 43.7% cobalt and 17.05% nitrogen, and 43.20% cobalt and18.72% nitrogen. When. used as catalysts in the hydrocyanation ofpropylene, the conversionv to isobutyroni trile was about with bothproducts.

XIII.

A cobalt carbonyl-hydrogen cyanidefcomplex was prepared as follows: Astainless steel reaction vessel was charged with 88 parts of puriedbenzene, parts of -cobalttetracarbonyL and 14 parts of hydrogen cyanide.The vessel was. pressured with 200 lbsl/sq; in. of nitrogen and heatedfor 8 hours at 130 C. .The pressure rose from 725 lbs/sq. in. at 130r Cjto 775 lbsz/sq. in. in 3' hours. and remained Vthere for the rest of therun. When the vessel. was cooled to room temperature., theresidual'pressure was 585 lbs/sq. in., indi-- eating thev loss of 'gasfrom. the cobalt carbonyl. The contents of the vessel were rinsed outwith. benzene. The reaction product was al linev purple powder,insoluble in: benzene, containing 37 6% cobalt and 21.4% nitrogen.

The. cobaltl carbonyl-hydrogen cyanide complex isolated above wasVplaced .in a silver-lined reactor with 27 parts of hydrogen cyanide and150 parts ofl propylen'e.l During'therst .4 hours at 130` C. thepressure vdropped from 290 'to 21.5` atmospheres'. After 1j5 hours thepressure was 210 atmospheres. There was obtained 29 parts (42%conversion 4of :hydrogen cyanide) of isobutyronitrile..-

.A catalyst having similar activity was produced by reacting cobalttetracarbonyl withl hydrogen cyanide -at '160 C. in furan as solvent.This complex. contained A23.65% cobalt and v 37.78 nitrogen.

A mixture of 56 parts of butene-l, 13.5y parts of hydrogen cyanideandl'l'parts of cobalt tetracarbonyl was reactedfor hours-atlo." C.,givingV 25.5% Aconversion to 2-methylbutyroniftrile'. vThe solidreaction product of cobalt 'carbonyl' with hydrogen cyanide remaining inthe reaction vessel contained v37.54% coba1tvand16;27% nitrogen. Thisspent catalyst was in turn used as hydrocyanation catalyst in a mixtureconsisting of 56 parts of butene-'1,"`13.5.parts .of hydrogen cyanideand 7 parts of the Sp'ent" catalyst. Reaction at 130 C. for 8 hours gave5.8% conversion to, 2-methylbutyronitrile. The residual solid contained31.59% 4 cobalt andv27`.51% .tilt-regen, showing that"theispent catalystrom'j-'the iirst run had reacted'further Awith hydrogen cyanide in thesecond run, giving fa product higher in nitrogen content and lower'in*c'olsiali','-content.-

silver-.lined 27:1parts :ofi ,theV mercury salt of Vcobalt carbonylhydri'de, 50 parts `of yhydrog" 'cyanide Jani-l 175' parts of propylene,and heatedv at 130 C. .for v1-'5 hours. LThe. nressurczdroppedjromainagdmum o glutaronitrile.

. 70. pressure vessel was charged fwith .emerso ofl 275-atmospheres to100 atmospheres vin two hours. There was recovered 79 parts (63.1%`

yield) of isobutyronitrile.

The mercury salt of lcobalt carbonyl hydride used in this and thefollowing example was prepared as follows?y i Twenty-nyc parts voffinely dvidedoobalt metal, 57.5 parts of mercurio chloride, 27 parts of.copper powder and. 71.3 parts. of anhydrous ether were charged into vacopper-lined vpressure vessel which had previously been swept free of.oxygen by means ofV a-stream` of' dry nitrogen, The vessel was; adjustedto maintain a pressure lof 1000 atmospheres of carbon monoxide.andheated for one lf'iour. at 150"y C., one hour atA 160 C. and tenhours. at 170 C'. The reactionyproduct was extracted three times with50' parts of ether, then the sol-id residue was extracted three timeswith 50 parts of' methylene` chloride. The ether and methylene chlorideextracts gave 27 andY 31 parte, respectively, of the mercurio salt ofcobalt carbonyl hydride, the total yield being 52% of thetl'ieoretical.y i

Analysis Calculated for HgECMColrlz; Hg. 38.0%.; Co,

Found: Hg, 37.00%.; Co, 21.76%; C, 17.73%.

The mercurio salt of. cobalt. carbonyl hydrlde is. az brightorange-yellow solid, stable in air, and slowly sublimable attemperatures below the de' composition point C. at 1 mm. pressure). Itis; insoluble'in water, soluble in ether, benzene andrrnethylenechloride. It. is attacked slowlyby concentrated oxidizing acids but isnot no ticeablyafiected by treatment with. concentrated hydrochloricacid.

EXAMPLE XVI A. stainless steel reaction vessel was cooled and chargedwith 27 parts of hydrogen cyanide, 55.2

parts of 1,3-butadiene, 27.1 parts of' themercuric.

salt of cobalt carbonyl hydride and 132 parts of benzene. The vessel wasclosed and heated under autogenous pressure at C.. for 'Ik hour, 'at 100C. for 3.5 hours, at A C. for one hour and vat C. for one; hour. Thereaction product was illtered. to remove the solid residue, which waswashedzwith 4.5 parts. of benzene. The combined benzene solutions werefractionaliy distilled to yield 4.8'3parts C. 35 parts of a mixture of-Bfpentenenitrile and 4 pentenenitrile, and 7.9 vparts of higher boilingnitriles which contained 2.9 parts of 2methyl The mixture ofpentenenitrile was shown. by infrared spectrograms to comprise 25% of4'.pentenenitrile and 75% of 3-pentene nitrile. i f

. .EXAMPLE-XVII Butadiene/cobalt.carbonyl hydrde was prepared asvdescribedr in application Serial No..

779,837, already referred to, by heating cobalt carbonyl 'andisopropanol at 130 C. yunder 100 atmospheres carbon monoxide pressurewhile in'- jecting 1,3-butadiene continuously. The product was isolatedas a liquid boiling at 32-33" C. at 2 m1n. -pressure. 1 i

A .stainless steel reaction :vessel was. charged with 4.6 parts ofbutadiene/cobalt carbonyl hy dride, .56.8 parts-of 1,3-butadiene, 27Vparte of hydrogen cyanide and 1.32 parte of; benzene. The vessel waspressured with carbon monoxide. to a' pressure of. 600 lbsfsq. in.,closed and heated at of 'ai material boiling at. i12-1389. whichcontained 2methyl-3'butenenitrile,'

The reaction product was filtered to remove a solid residue. which waswashed with 8.5 parts of benzene. The combined filtrate and Washingswere fractionally distilled, yielding 6.9 parts of mixedpentenenitriles. Infrared spectrograms showed that the pentenenitrilefraction contained 28.5% of 4-pentenenitri1e, the remainder being3-pentenenitrile.

EXAMPLE XVIII A stainless steel bomb was charged with 56 parts ofoctene-l, 17 parts of cobalt tetracarbonyl, 8.5 parts oftriphenylphosphine and 27 parts of hydrogen cyanide and heated for 8hours at 130 C., the maximum pressure reached being 650 lbs/sq. in. Thecontents of the bomb were rinsed out with ether, filtered and distilled.There was obtained 16.5 parts (23.7% yield) ofalpha-methylcaprylonitrile, B. P. 209 C. at 75l mm. pressure, 1113251.4181.

Analysis Calculated for C9H11N: C, 77.7%; H, 12.2%; N,

10.1%. Found: C, 77.6%, 77.3%

I-I, 11.6%, 11.7%; N, 10.2%, 10.1%.

EXAMPLE XIX A stainless stell pressure vessel was charged with 22 partsof methyl -hexenoate, 27 parts of hydrogen cyanide and 17 parts ofcobalt tetracarbonyl and heated at 130 C. for 8 hours, the maximumpressure being 28 atmospheres. Distillation of the product afterfiltering off the spent catalyst gave 4.9 parts (19.3% conversion) of amole for mole hydrogen cyanide adduct of the formula CHiaOzN.

Analysisl Calculated for CsHiaOzN: C, 61.9%; H, 8.4%;

N, 9.05%. Found: C,l61.85%; H, 8.70%; N, 8.77%.

EXAll/[PLE XX A stainless steel bomb was charged with 19 parts of-hexenenitrile, 17 parts of cobalt tetracarbonyl and 27 parts ofhydrogen cyanide and heated for 8 hours at 130 C. After filtering anddistilling the product, there was obtained 8.7 parts (35.6% conversion)of a dinitrile of formula CvHioNz, 111,25 1.4348, which was probablyalpha-methyladiponitrile.

Analysis Calculated for C'zHioNz: N, 22.9 Found: N, 22.7

The -hexenenitrile used in this example was prepared according to thegeneral disclosure of application Serial No. 101,905, filed on June 28,v

1949, by Albisetti and Fisher, by heating a mixture -of-50 parts ofacrylonitrile and 200 parts of propylene for four hours at 240 C. and1000 atmospheres pressure. Distillation of the reaction.

product gave hexenenitri1e, B. P. 162 C. at atmospheric pressure.

EXAMPLE XXI A stainless steel reactor was charged with 68 parts ofisoprene, 88 parts of benzene, 17 parts of cobalt tetracarbonyl and 27parts of hydrogen' cyanide and heated at 130 Cjfor 18.5 hours, the.

maximum pressure being 725 lbs/sq. in.4 'Ifhe'e'cof-ltents of thevreactor were'rin'sed out with ben-1" zene,l filtered and distilled.There was obtained' 1s-paris (50.5%.yie1di of a monentrle 'which' Astainless steel bomb was charged with 27 parts of hydrogen cyanide, 17parts of cobalt tetracarbonyl, and 54 parts of vinylcyclohexene (thedimer of 1,3-butadiene) and heated at 130 C, for 19.5 hours, thepressure being 700-675 lbs/sq. in. There was obtained 9.5 parts (14.1%yield) of the mononitrile, alpha methyl 3 cyclohexene -l-acetonitrile.

Analysis Calculated for CsHiaN: C, 80.0%; H, 9.6%; N,

10.4%. Found: C, 79.48% H, 9.89%; N, 10.36%.

The product was further identified by hydrogenation of the double bond,followed by hydrolysis to an acid identical, by mixed melting point,with the acid obtained by hydrogenation of the aromatic ring in anauthentic sample of hydratropic acid.

EXAMPLE XXIII A stainless steel reactor was charged with 41 parts ofbiallyl, 27 parts of hydrogen cyanide and 17 parts of cobalttetracarbonyl and heated for 8 hours at 130 C. There Was obtained 12.7parts of a mononitrile fraction, B. P. 15G-160 C. at 760 mm. pressure,and 5.2 parts of a dinitrile fraction, B. P. 13o-150 C. at 20 mm.pressure.

EXAMPLE XXIV A stainless steel reactor was charged with parts ofdicyclopentadiene, 27 parts of hydrogen cyanide, 8.5 parts oftriphenylphosphine and 17 parts of cobalt tetracarbonyl and heated at C.for 15.5 hours, the pressure being 660-625 lbs/sq. in. There wasobtained 17. 4 parts (24% yield) of a mononitrile having the formulaC11H13N.

' Analysis calculated for cnHiN: N, 3.8%. Found: N, 8.5

EXAMPLE XXV `Bicyclo [2.2.1]-5-heptene-2-carbonitrile,

Ho CH-CN CH: I H \|/CHa CH was prepared by condensing cyclopentadienewith acrylonitrile (see Bruson, J. Am. Chem. Soc. 64, 2457-61, (1942)).charged with 167 parts of bicyclo [2.2.1]-5- heptene-Z-carbonitrile, 54lvparts of hydrogencyanide, 51 parts of cobalt tetracarbonyl and 25 partsof triphenylphosphine and heated for 8 hours at 130 C; There wasrecovered l30 parts of'starting material and 126 -parts (62% conversion)`of a dinitrile which was a semi-solid at room temperature. This was amixture of posi- @tion and/or geometrical isomers. A solid and a Astainless steel reactor Was- 15 perature of atleast 50ev C. and in'thejpi'esence of acobalt carbonyl catalyst.-

3. Process for the preparation of nitril'es which comprises reacting4-pentenenitri1e with hydrogen cyanide at a temperature of at least 50C. and in the presence of a cobalt carbonyl catalyst.

4. Process for the preparation of nitriles which comprises reacting anitrile R-CN where R is a monovalent aliphatic olenic hydrocarbonradical having the carbon carbon double bond at least two carbonsremoved from the free valence and having hydrogen on each carbon of anethylenic linkage with hydrogen cyanide at a temperature of at least 501C. and in the presence of a cobalt carbonyl catalyst.

5. Process for the preparation of nitriles which comprises reacting anethylenically unsaturated nitrile having the ethylenic unsaturationisolated from the nitrile group and having hydrogen on both carbons ofan ethylenic linkage with hydrogen cyanide at a temperature of at least50 C. and in the presence of a cobalt carbonyl catalyst.

6. Process for the preparation of nitriles which comprises reactinghydrogen cyanide with an ethylenic compound of 2 to 12 carbon atomshaving ethylenic unsaturation as its only open chain carbon carbonunsaturation and having hydrogen on both of the carbons of an open chainethylenic linkage, any valences of ethylenically bonded carbons notjoined to hydrogen being joined to carbon whose valences not joined tohydrogen are satised by carbon, by bringing the reactants in contactwith each other and with a cobalt carbonyl catalyst.

7. Process of claim 6 wherein thecontact is at 8. Process of claim 6wherein the ethylenic compound is a member of the class consisting ofhydrocarbons and cyanohydrocarbons.

9. In the addition of hydrogen cyanide to'compounds having an ethylencgroup with hydrogen on both carbons thereof, the improvement wherein thereactants are brought into contact in the presence of a cobalt carbonylcatalyst.

10. A process for the preparation of nitriles which comprises reactinghydrogen cyanide with an ethylenic compound of 2 to 12 carbon atomshaving ethylenic unsaturation as its only open chain carbon carbonunsaturation and having hydrogen on both of the carbons of an open chainvethylenic linkage, any valences of ethylenically bonded carbons notjoined to hydrogen being joined to carbon whose valences not joined tohydrogen are satised by carbon, by bringing the reactants in contactWith each other and with a cobalt carbonyl catalyst, said catalyst beinga reaction product of hydrogen cyanide with cobalt carbonyl, Co2(CO)s,blue-purple in color, of 23- 44% cobalt content and 16-38% nitrogencontent, and soluble in aqueous potassium cyanide solution with theevolution of carbon monoxide to an aqueous solution which on heatinggives potassium cobalticyanide.

1. PROCESS FOR THE PREPARATION OF A PENTENENITRILE WHEREIN BUTADIENE ISBROUGHT INTO CONTACT WITH HYDROGEN CYANIDE AT A TEMPERATURE OF AT LEAST50* C. AND IN THE PRESENCE OF COBALT CARBONYL, CO2(CO)8.